Model Updating of a Freight Wagon Based on Dynamic Tests under Different Loading Scenarios (original) (raw)
Related papers
2007
This paper presents the findings of an investigation into the structural properties of a double deck passenger railcar. The objective of the investigation was to develop an in-service dynamic model about an operational point where the car was travelling at 80km/h over track used in everyday service. A detailed grid of response measurements, providing a spatial definition of the car, were recorded consisting of nearly three hundred accelerometer records in three axes distributed over the structure in more than forty measurement batches while the car was running down the track. Using these measurements, an in-service modal model was constructed by operational modal analysis using the enhanced frequency domain decomposition technique. Of particular interest to this investigation were the primary vertical and lateral bending modes which were found to be coincident, with the lateral mode dominating. The application of whole body vibration weightings however, produced an equivalence of th...
Dynamic response of railroad vehicles: a frequency domain approach
A very elaborate Finite Element (FE) model and a rigid body model of a typical electrical multiple unit trailer coach are described. These models were used to find the dynamic response to track irregularities in the frequency domain. The Power Spectral Density (PSD) of track irregularities was used as input to the system. The influence of different track irregularities on dynamic response and coupling between vertical and lateral dynamics was investigated. Extensive experiments were carried out, and analytical results were compared with the measured response.
Estimation of Applied Forces on Railway Vehicle Wheelsets from Measured Vehicle Responses
International Journal of Vehicle Structures and Systems, 2009
In this paper, a finite element (FE) model of a railway freight vehicle is proposed to be used in the identification of applied forces to the wheelsets. The proposed model is comprised of two, two-axle bogies of type H665 and a freight wagon. The model is updated in two stages. First, the bogie is updated by using modal data extracted from measurements on an actual bogie separated from wagon. Secondly, the whole structure of the vehicle is updated by modal data obtained from a test conducted on the vehicle in the laboratory. Since the proposed model is relatively large, it is reduced to some desirable points through the superelement analysis method, in order to reduce the cost of computation. The final reduced model is then used to identify the applied forces resulted from irregularities of track.
A New Strategy for Dynamic Weighing in Motion of Railway Vehicles
IEEE Transactions on Intelligent Transportation Systems, 2015
Questa versione della pubblicazione è conforme a quanto richiesto dalle politiche dell'editore in materia di copyright. This version of the publication conforms to the publisher's copyright policies.
Canadian Journal of Civil Engineering, 2022
An Irish Rail intercity train was instrumented for a period of one month with inertial sensors. In this paper, a novel calibration algorithm is proposed to determine, with reasonable accuracy, vehicle model parameters from the measured vehicle response data. Frequency domain decomposition (FDD) is used to find the dominant frequencies in the captured data. Randomly chosen 2 km data segments are chosen from a number of datasets, thereby averaging out the effects of variations in track longitudinal profile, track stiffness, signal noise and other unknowns. The remaining dominant peaks are taken to be vehicle frequencies. An optimization technique known as Cross Entropy is used to find vehicle mass and stiffness properties that best match modal vehicle eigenfrequencies identified in the frequency analysis. Finally, the calibrated vehicle is run over a measured track profile and the resulting model output is compared to measured data to validate the results.
Structural Dynamic Analysis of Freight Railway Wagon Using Finite Element Method
Procedia Materials Science, 2014
This paper describes the development of a virtual freight wagon vehicle using virtual prototyping computer tools. The freight wagon considered as open type wagon "BOXN25" of the Indian Railways. The freight wagon vehicle comprises of car body structure and two bogies. Solidworks is used for modeling the freight wagon and the geometry is exported to finite element tool, ANSYS. A multi degree of freedom system has been reviewed and compared with system having infinite degree of freedom (continuous structure). The current problem falls in the category of large models (Block Lanczos Algorithm is used) and has high degrees of freedom (PCG Solver is used). The structural dynamic response for the virtual freight wagon is determined. It is seen that the car body deformation is influenced by its elastic underframe and sidewalls. The influence of vibration modes, which describe local deflection, on the comfort level and stability of laden goods is discussed. Mode shapes up to a frequency of 30 Hz are considered.
Railcar Dynamic Response during Braking Maneuvers Based on Frequency Analysis
Applied Sciences
The dynamic response of a vehicle during braking is influenced by the tangential forces developed at the wheel-rail’s contact surface. The friction coefficient affects the load transfer from the wheel’s tread to the vehicle. In this work, the vibrations of a scale-down railway vehicle are monitored during braking and their relationship with the friction coefficient between wheel and rail is found out. The vehicle is instrumented with encoders, accelerometers, and is controlled via Bluetooth. The tests are carried out with clean and friction-modified rails. The tangential forces transmitted from the wheel to the railcar’s body are visualized in time and frequency using a proposed correlation algorithm based on the outputs of the Continuous Wavelet Transform (CWT). The results demonstrate that tangential forces have a significant impact on railway vehicles under conditions of high friction coefficients and large creep values.
A Novel Methodology for Dynamic Weigh in Motion System for Railway Vehicles With Traction
IEEE Transactions on Vehicular Technology, 2019
Loading conditions of railway vehicles both affect the vehicle and substructure directly. There are approaches to determine the load of a railway vehicle, the first one is to statically weigh the vehicle, the second approach is to place sensors along the track and dynamically weigh the vehicle at certain sections and the third one is to design special sensors that can be implemented on the vehicle. In this study, a model based indirect estimation methodology for normal load is proposed. This approach is based on interpreting angular velocities of wheels and translational velocity measurements of a vehicle to determine the normal load. A swarm intelligence based evolution of multiple models is proposed for estimation. In order to validate the approach, measurements taken from a tram wheel test stand with an independently rotating wheel are considered. The proposed approach is promising to be used as a dynamic weighing system and cost-efficient since only vehicle-based sensors are used. Furthermore, a continuous monitoring of the normal load is made possible with high accuracy since this methodology is neither limited to track-based sensors nor it requires special sensors and instrumented wheelsets.
Challenges in Railway Vehicle Modeling and Simulations
Rail vehicle dynamic is a very complex system, in past many year it has progressed a long way from its origins as a research tool. In modern time many multibody simulations software packages are used to design various essential part of the design process for new vehicles as well as for existing vehicle for their service problem. Increasingly, simulation is being used as part of the vehicle acceptance process in place of on-track testing. This state of the art paper surveys the current applications for rail vehicle dynamic modelling. The way of simplifying the complex mechanical system into a mathematical representation is invariably subject to compromise and open to individual interpretation. In this real world the availability of information leads selection of idealisation of various components will depend on the application. This paper discusses appropriate modelling choices for different applications, and comments on best practice for the idealisation of suspension components, wh...
Development of an innovative weigh in motion system for railway vehicles
2013
The estimation of the axle loads of running railway vehicles in motion is an important topic in the management of railway networks, basically for purposes of safety and maintenance interventions on the track. To this aim, through a reasonable number of specialized measurement stations, the axle load of the vehicles circulating in a railway network can be easily estimated without any significant consequence on the railway traffic. In this work the authors present the development of an innovative algorithm for WIM systems aimed at estimating, by means of track measurements, the axle loads of a generic train composition. The formulation of the proposed algorithm is quite general and it can work on different sorts of track measurements (rail shear, rail bending, vertical forces on the sleepers as well as on a combination of them); consequently it can find application in different typologies of measurement stations. The set of experimental physical quantities chosen as inputs are properl...